Process of applying abrading material to grinding mechanism.



J. A. BBGHTEL.

PROCESS OF APPLYING ABRADING MATERIAL 'I'O GRINDING MECHANISM.

APPLICATION FILED JANv 15, 1913.

mfimw Patented Mar. 10, 1914.

4 SHEETS-BHEET 1.

WITNESSES: IN V EN TOR.

W/w v V4 (A J. A 'BBOHTBL.

PROCESS OF APPLYING ABRADING MATERIAL 'IO GRINDING MECHANISM.

AZ-PLIUATION FILED JAN.15, 1913. j fli jgfigwfi Patented Mar. 10, 1914..

-; SHBE'1S-BHEBT 2.

2 a. I M 4 m M N W mnm H v 1 r a L w a.

L A. BECHTEL.

P11003555 0F APPLYING ABRADING MATERIAL To GRINDING msommsm. APPLICATIONFILEDJAN. 16, 1918. g gggfigg Patentefl Mar. 10, 1914-,

4 SHEETS-SHEET 3.

m M m m" E J. A. BBGHTEL. PROCESS OF APPLYING ABRADING MATERIAL POGRINDING MECHANISM. APPLICATION FILED JAN,15, 1913.

1,089,895 Patented Mar. 10, 1914.

4 SHEETS-SHEET 4.

ATTORNEY UNITED snares rirrnrrr carton,

JOHN A. BECHTEL, 0F TARENTUM, PENNSYLVANIA, ASSIGNOR TO PITTSBURGH PLATEGLASS COTEPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENN-SYLVANIA.

Specification of Letters Patent.

Application filed January 15, 1913.

Patented Mar. 10. 1911.4.

Serial No. 742,224.

To all whom it may concern:

Be it known that 1, JOHN A. Bnorrrnn, a citizen of the United States,residing at Tarentum, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements inProcessesof Applying Abrading Material to Grinding Mechanism, of whichthe following is a specification.

The invention relates to a process for applying ahrading material togrinding mechanism, and involves the use of apparatus such as thatillustrated and described in my co-pending application Serial No.715,126, filed August 14:, 1912. The invention has for some of itsprimary objects the provision of a process wherein the amount ofapparatus for its practice is reduced to a minimum, and of such simplecharacter as to be easily operated by unskilled labor; the provision ofa process wherein the abrading material is prevented from setting; theprovision of a process in which the mixture of abrasive and water iscirculated in such manner as to equalize the capacity of the system forall the grades employed; the provision of a process whereby that portionofthe abrading material not suitable for the grinding work being done atany particular time is separated and held in readiness for futureoperations; the provision of a process in which the waste of ahradingmaterial is substantially eliminated, and the provision of a processwherein abrasive of different degrees of fineness or the same degree offineness may be simultaneously supplied to a plurality of grindingmachines without interference.

One type of apparatus bywhich the process may he practised isillustrated in the aceoi'npanying drawings, wherein Referring first tothe general arrangenient of parts as shown in Figs. 1 and 2, i\-.-:.Lare grinding tables which may he of any approved type and driven in theusualmanner; 13- 15 and C-C are the runners ordinarily employed in thegrinding of plate glass, which runners are 01 the usual construction andsupported in the usual way; D-D are the troughs or drainage receptacleslying beneath and encircling the F is a drainage pit or sump to whichthe mixture of sand and water from the troughs D-D is conducted throughthe passages G; H is a rotary pump for carrying the mixture of sand andwater in the sump F to the grading tank E; H is a bin containing freshsand which is adapted to be supplied from time to time from the bottomof the bin to the sump F through the door I; and K-K are troughs leadingfrom the grading apparatus to the two grinding mechanisms, such troughscommunicating at their lower ends with transverse conductors Tiperforated on their lower sides and extending across the grinding tablesso as to supply the mixture of sand and water uniformly over suchtables. In the arrangement just described, one grading apparatus isillustrated as taking care of two sets of grinding mechanism, but itwill be understood that this arrangement is merely illustrative,

and that the grading mechanism may be used with any desired number ofgrinding inechauisms dependip upon its capacity. In operation, thematerial supplied through the troughs K to the grinding tables, afteruse upon such tables is drained into the troughs D and returns to thepit or sump F from which it is pumped to the grading tank It by means ofthe pump H, so that the material is used over and over again, thematerial too linefor use being washed out over the top of the tank ashereinafter described, and fresh sand being supplied. from the bin Hfrom time to time to take the place of i readily understood byrei'erence to figs. i and 5. The lower portion 1 of the grading tank E1s conical 1n form, while the in s pump being provided with an inlet s eetior carrying the materialto be graded,

irons thesurnp' F to the pump, and has an "let pipe 5 leading intothelower end of illustrated, two sets. oi pipes 6 and tion oi the tank andhave connected to their ends which lead through the sides of thetank,.the flexible pipes 8 and 9. Either into troughs K leadingto thegrinding mechanisms. The other flexible pipe or see which do not'lead tothe troughs K pee ll. leading to the sump Susded in the cylind calportion 2 of the it are pair-of flexible tubes 12, which open at theirupper ends and at lower ends pass through the side of the "tan": andcarry the flexible tubes 13. These flexible tubes 13 can be made todischarge either into the troughs K or into the boxes a The tubes 12 aresuspended by means the cores lower end of each of the cords 13 beingdied with a chain 15 which may be to engage a securing device (notshown) whereby the upper ends of the flexibl pipes 12 may be held at anydesired eleoverflow opening 16 provided :ent the upper edge of the tank,fromwhich. opening a pipe 1? (Fig.1 5) conducts the waste material suchas mud and sand'too fine for use, tothe sewer or. some other wastereceptacle.

portions 2 of the tank is an outlet pipe 18 .extendingdown into the tankas indicated serve a function to he hereinafter described.

As indicated in Fig. 3', the bottom of the sand bin H is'forined withconverging walls 23--5E3, and the joining edges of these sidessiopetoward the sunip F as indicated in Fig. "l. oi this arrangement, the abe readily conducted to being controlled by or the sandidown thecharacterfoi the grading apparatus portion 2 thereof is cylindrical, lheit is driven-from. a motor (Fig. 5

Qrfiding tank E.. In the fornrof appa iroin diiierent levels in theconical por-" forced up through the gradin tank or both oi the pipes 8and 9 may be directed s harge into the boxes 10 provided with,

1' passing over the pulleys 1e,

intermediate the ends of the cylindrical in dotted lines and governed bythe valve 19,: andleading to the trough 20 are twobranches 21'. Thistrough 2O surround ng ditches D -D; underneath. the tables and l. Inorder to iainclined bottomof the'bin, the pipes 26 are providedalong'the inclined sides of the bottom as indicated in Fig. 3,'and athird pipe 27 extends along theextreme lower edgeof the .bin. Thesepipes are supplied withwater outlets, and by this means the feeding ofthe sand out of the bin and to the sump F- is greatly facilitated,- andall of. the sand-in the bin may be fed .out without difiiculty.

The ball check valve 28 governs'the'openin at the lower end ofthedraining tank, sue ball valve being operated by means of the rope 29extending-over the pulleys shown.

It will be seen that whenthe pump is operated, the material from the sumF is the'sand in the water is grade according to its size,- thelargerparticles occupying a p'o sitionadjacent the bottom of'the tank, and thegrades becominghfiner'and finer asv the.

top of the tank is approached. For the first 1 rough grinding of theplate of glass, the

coarse grades of'sand are required, and in the operation of theapparatus when the grinding is first-be un the flexible pipe 8 connectedto the pipe 6 is introduced into the trough K, the other pipes 9 and 13carrying the finer grades 01. sand and being in position so as todischarge into the box 10. W hen the grinding has progressed for a giventime, and a finer grade of sand is re quired, the pipe or hose 8 iswithdrawn from the trough K and the pipe or hose QIinserted in suchtrough. ,After thev grinding with thisparticulargrade has beenconcluded, the

upper end of the pipe or hose 12 is lowered to a position adjacentthe'lower end of the cylindrical part 2 of the tank or tea level in thetank occupied by the exact grade de-. sired, and the pipe 13 is placedin the trough K,'.the pipes 8 and 9 at such time discharging into thebox 10.- Asthe'grinding pro-' grosses and liner and finer grades of sandand are required, the pipe 12 is'raised step by step by means of chain15 at the end of cord 13 until the finest grade of sand is. used, andthe grinding operation is concluded. The several links-in the chain; notonly serve to secure p'ipe12 in the proper position by engaging with thestop not shown, but it also enables the operator to determinetheexactposition of the free end of theflexiblefipipe- 12 in the grading.apparatus so he "thereby knows the exact. gradejofabrasiye being deflivered to thei'grinding. mechanism at any stage of the oporation n isdesirable'during'the opera-i911 s just describedthat the upward.velocity; inthe tank may be-such that none of the sand suitable for useshall be Washed through the. outlet- 16," and in orden to regulate thisup- ;ward-velocity of the water through the up perpprtion of the tankand prevent a Waste ojfanyotthe' grinding sand, the-outlet pipe 18controlled by the valve-19 is provided.

order to wash it out.

The opening of this valve 19 reduces the up- 'ard velocity of the waterin the tank above the lower end of the pipe 18 to such an extent thatonly the mud and those portions of the sand unsuitable for grinding arewashed away through the overflow 17. The mixture thus withdrawn throughthe outlet 18 passes through the trough 20 and thence through the pipe22 to the trough or gutter I) (see l), and thence back to the sump F.The material thus withdrawn is therefore not wasted, but is returned foruse, and the returning of the mixture to the gutter D performs a usefulfunction in that it assistsin washing out the gutter and keeping itclean, thus reducing or eliminating the amount of clean water whichwould otherwise have to be. furnished to the gutter in The mixture offine sand and water, because of its specific gravity, constitutes abetter washing medium for the coarse sand in the trough than clearwater. The placing of the valve 19 above the inlet to the pipe 18 isadvantageous in that the head of water at the valve 19 and its velocityis reduced, thus reducing the cut ting action of the sand on the valve.Similarly the use of the trough 20 is advantageous, as the pipes 21discharge into such trough at relatively low velocity, whereas if suchpipes were connected directly with the pipe 22, the suction from suchpipe 22, due to the added head, would increase the velocity. of flowpastthe valve 19 and the consequent cuttingaction of the sand.

It will be seen from the foregoing that the operation of the apparatusis substantially continuous and that the amount of waste is reduced to aminimum. Any desired quair tity of any desired grade of sand may bewithdrawn from the tank at any time without disturbing the grades aboveor below the, point of withdrawal, and the apparatus is always incondition for use. When the grinding mechanism is not beng operated, allof the pipes or hose 8, 9, and 1.3 discharge into the box 10, and thematerial is returned to the sump F and again circulated through theapparatus. The pump H may thus be made to operate continuously,regardless of the operation of the grinding mechanism, and as a result,the sand in the water is maintained continuously in suspension, andthere is no clogging of the parts due'to the mttling of the sand. v

It will also be readily understood that no matter whether one or moregrinders are in operation or Whether. no grinder at all is in operation,the discharge from the various pipes leading from the grading tankremains constant, thus insuring the same upward velocities in all of theliorizontal planes in the grading tank so that irrespective of theclniracter of the work that is being done, the val. will always lie atapproximately the same position in the grading apparatus, thus insuringa uniformity of operation not easily otherwise obtained.

It will also be apparent that due to the small capacity of the lowerpart of the conical portion of the'cone, the capacity of the grader tohold the larger grades of coarser particles is comparatively small inproportion to that part of the grading apparatus which holds the finerportions of grading material; but inasmuch as these coarser grades arecontinuously discharging from the lower portion of the cones into thesump 1*, the capacity of the system to hold the lower grades isincreased by the capacity of the sump F. This increase of the capacityof the system is very advantageous as it enables the apparatus to beoperated under widely varying conditions as regards the amount of coarsesand that is. introduced into the system from the bin H. If it were notfor this feature of the apparatus and too great a quantity of sand wasintroduced into the system, the coarse sand would accumulate in thebottom part of the grader E and seriously interfere with its operation.On the other hand, the upper portion of the tank above acts as acollector or trap for fine sand, such fine sand accumulating until thedesired proportion of sand to water necessary for the best results ingrinding is secured. This upper portion of the tank thus constitutes asupplemental grader superposed upon the lower part of the tank.

Furthermore, the labor of getting the sand'into suspension again,incident to an intermittent operation, is eliminated,.and the apparatusis in condition for operation just as soon as the grinding mechansm isin 105 shape to receive the sand. Another advantage incident to theprocess is due to the factthat a plurality of grinding mechanisms may befed from the same grading apparatus, and this operation may be carriedon 110 whether the stage of grinding is the same inv the variousgrinding mechanisms or not; that is, rough grinding may be carried oninone grinding mechanism while fine grinding is being carried on inanother mechanism, 115 such function being incident to the fact that onegrade may be withdrawn from the apparatus without interfering with theposition of another grade.

As a further function incident to the use 120 of the regulating valve19, it will be seen that the use of this valve permits any de-' siredupward velocity of fluid inthe tank below the lower end of the pipe 18without I increasing the velocity above such lowerend 125 or withoutwashing away any of the sand suitable for use, through the overflow 16.This permits the changing of the speed of the pump H to give any desiredgrade from the pipes 6, 7 or 12, without increasing the overflow andconsequent waste. It will be seen that all of thesand inthe system isalways ready for use, so that the capacity of the system is governedonly by the combined capacity of the sump and grading tank.

Another great advantage of the process is that no valves are required toregulate the character of the mixture, which, from the variousoperations in the tank, -"goes either to the sump or the grinding table,it being extremely diflicult to get a valve which will stand the cuttingaction'of the sand and remain tight, and it is extremely important thatwhen the finer gradesof sand are being conducted to the grinding table,io'ne of the coarser grades should be allowed to get onto the grindingtable, as this would greatly impair the quality ofthe work done.

It will also be readily understood that by use of the swinging conductor12 which is adapted to be raised and lowered through a wide range in thegrading tank, it is pos si is, at will, to withdraw any of the gradesfrom the grading tank without disturbing any of the other grades orwithout with drawing all of any of the grades contained therein, so thatit is possible by gradually and uniformly raising the end of the fleiiible conductor 12 while still. retaining a large quantity of all of thegrades of the abrasive accurately gradedv in the grading vessel, towithdraw successively a portion of each of these grades ranging from thecoarsest to the finest, each grade following the precedrnebyimperceptible changes so that the character of the surfaces beingground on the grinder can be readily brought frointhe state of roughnessto the state of extreme fineness desired, in the most natural manner andin the shortest possible period of time. It will be apparent that theinvention is capable of embodiment in various forms of structure withoutdeparting trom'the spirit of the process.

may be similarly varied to supply any desired number of grades. Thegrading tank shown is of conical fOrni-anddischarges by gravity, but itwill be apparent that this is not necessarily the case, as the mixturemight charge from such pipe be directed to grinding mechanism. Similarlyas to the feature of continuously circulating the new terial through thetank W1thOUt-PQSS1Dg to "the grinding machine when such grinding machineis out of operation, such method of The number of grinding mechanismsfed from a single grading tank- 'may be varied to suit conditions, andthe a number of withdrawing pipes in the tank operation being just asapplicable to a grad-I invention. 7 p

The process is obviously not limited in its application to the grindingof the faces of sheets of plate glass, but may be utilized in otherglass grinding or smoothing operations, and on varioussubstances-besides glass wherein abrasive-and'water are employed, thedrawings and description be- Other avithcut departing from the spirit ofthe ing merely illustrative of one important use of the process. In somecases it may be desirable to use only one grade of abrasive with eachgrinding or smoothing HIQChEL nism and shift the article from a mccha-Inism supplied with one grade of abrasive.

to another mechanism supplied with an other finer grade of abrasive, thenumber of shifts and mechanisms being dependent upon the character ofthe surface being reduced. v n Having thus described my invention, whatI claim as new and d sire to secure by Letters Patent, is the following:

1. The method of applying abrasive to grinding mechanism, which consistsin grading the abrasive in suspension in water a receptacle, conductingany desired grade to the grinding mechanism, collecting the drainage ofabrasive and water from' the grinding mechanism, conducting portions ofthe grades m the receptacle not being used to the drainage collected andreturning the drainage to the grading receptacle during the period inwhich the said desired grade is being conducted to the grindingmechanism, the

said operation being conducted in an uninterrupted cycle.

2. The. method of applying abrasive to grinding mechanism, whichconsists in sup- I plying a mixture of one of the grades of the abrasiveand a liquid from a grading receptac-le to thegrinding mechanism andre-- turning the mixture'to the receptacle in an uninterruptedcycle,while maintaining the other grades of. abrasive in the receptacle insuspension in the liquid, and simultaneously circulating such othergrades to a position removed from the receptacle and back through thereceptacle to their original'positions in the receptacle.

3. The method of handlingiabrasive for grinding mechanism, whichconsists in grading the abrasive in suspension in water in a receptacle,conducting mixture of the abrasive and water to the grinding mochanisniand thenceto a drainage receptacle and back-to the grading receptacle inan uninterrupted cycle during the grinding operation, and continuouslycirculating the mixture of abrasive and water to the drainage receptacleand back to the grading receptacle when the grinding operation is notbeing carried on, the portion of the abrasive in the receptacle at suchtime being graded by the circulation.

4. The method of applying abrasive to grinding mechanism, which consistsin collecting a mixture of abrasive and water from a grinding mechanism,forcing such mixture upward through a grading tank containing a mixtureof abrasive and water, thereby grading the mixture, conducting a portionof the mixture from one level in the tank to the grinding mechanism, andsimultaneously returning other portions of the mixture from otherdiiterent levels in the tank to the mixture collected fronrr thegrinding mechanism, the cycle being sub stantially a continuous anduninterrupted one aslong as the grinding continues.

5. The method of applying abrasive to grinding mechanism, which consistsin col lecting a mixture of abrasive and water from a grindingmechanism, forcing such mixture upward through a grading tank containinga mixture of abrasive and water, thereby grading the mixture, conductinga portion of the mixture from a level intermediate the top and bottom ofthe tank back to the mixture collected from the grinding mechanismwithout passing to such mechanism, whereby the upward velocity of thewater in the tank above the said level is reduced, and conductingportions of the mixture in the tank below and above the said"levelsuccessively to the grinding mechanism, the operations of forcingthe mixture upward through the grading tank, conducting a portion of'themixture from the said level in the tank; and conducting another portionof the mixture to the grinding mechanism being carried onsimultaneously.

6. The method of applying abrasive to av plurality of grindingmechanisms operating simultaneously, which consists in gradlng theabrasive in suspension in water in a receptacle, simultaneouslyconducting por tions of the .diiferent grades or the same grade to thedifferent grinding mechanisms, dependin upon the stage of grinding ofeach madhine, efid, returning thedrainage from the grinding mechanismsto the said receptacle the circulation from the receptacle to thegrinding mechanisms and back being an uninterrupted one.

7. The method or applying aln-asire to a plurality of grindingmechanisms operating ,imultaneously, which consists in collecting themixture of the abrasive and water from the various-grinding mechanisms,forcing such mixture upward through a grading tank containing a mixtureof abrasive and water, thereby grading the mixture, and conductingportions of the mixture from ditt'erent levels in the tanksimultaneously to the said grinding mechanisms, the said operationsconstituting a continuous cycle.

8. The method of applying abrasive to a plurality of grinding mechanismsoperating simultaneously, which consists in. collecting the mixture ofthe abrasive and water from the various grinding mechanisms, forcingsuch mixture upward through a grading tank containing a mixture ofabrasive and water, thereby grading the mixture, conducting portionsoi": the mixture from different levels in the tank simultaneously to thesaid grinding mechanisms, and at the same time conducting portions ofthe mix ture in the grading tank containing grades of abrasive not beingused backto the drainage collected from the various grinding mechanismswithout passing to such mechanisms, the said operations constituting acontinuous cycle.

9. The method oi :qmlying abrasive to grinding mecl'ranism whichconsists in collecting the mixture oi abrasive and water from thegrinding mechanism, eliminating the superfluous water and finestabrasive from 'the mixture, returning the coarsest abrasive to thegrinding mechanism during the period in which such. coarsest abrasive isrequired in the grinding operation, and returning such coarsest abrasivedirectly to the mixture collected from the grinding mechanism withoutpassing to the grinding mechanism, when such coarsest abrasive is 'notrequired by the grinding mechanism, the said operations constituting acontinuous cycle.

In testimony whereof I have hereunto signed my name in the presence oi.the two subscribed witnesses.

JOHN A. BECI-IEEL.

Witnesses:

Ln'rrrm A. M'i'uus, Anonwon'rn M A max

